This invention refers to a fastening unit for blocking the items to be processed on the working plane of a tooling machine, designed in particular for woodworking purposes. This is a unit mounted on supports designed to be positioned on the working plane of a tooling machine, comprising suction devices capable of ensuring the blocking of items such as a panel or the like placed on the working plane, as well as pressing elements capable of clamping the item at its edges, so as to allow, thanks to the fact that these fastening units can be shifted and positioned on the plane at will, even items of complex shapes to be blocked and processed quickly and easily.
The fastening unit according to the invention presents the support holding the item in a manner which is mobile in height, so as to enable the fastening unit to be inserted around the item and to adapt the level of the holding plane to any deformations an/or curvatures of the item itself.
The fastening unit according to the invention is particularly suitable for application on woodworking machines such as illustrated by the U.S. Pat. No. 1,270,691 by the same Applicant.
This patent describes a machine for the processing of panels in which the working plane comprises a pair of guides arranged along a first axis, on which a multiple number of cross beams are allowed to slide while carrying each one or more mobile fastening devices mounted on the cross beams along an axis orthogonal to the previous axis.
Each support is equipped with suction devices capable of ensuring the blocking of a panel placed on the working plane, and each support also offers a hollow capable of being engaged by an element such as a pin or the like mounted on the machine""s operating head, so as to allow using the same tooling head to shift these supports along the working plane until moving them to the required position.
As mentioned above, in these known machines the fastening of the items occurs by depression, by placing the item on suction elements connected to aspirating devices capable of creating a vacuum inside the suction cup and of blocking the panel during the processing step.
While this system works well on the panels, it nevertheless exhibits a few shortcomings when it comes to the processing of items of a limited width and complex shape, which must be processed on all sides and are difficult to position and block on the working plane. In these cases, at the present state of the art some machines are used which comprise a series of suction cups on which the item is placed, and a series of separate pressing elements mounted on a support provided above the working plane, which must be mounted and removed manually. The pressing element s are lowered to firmly clamp the item the suction cup would be unable to hold during the processing phase. This involves the need to have two series of devices, suctions cups and pressing elements respectively, where the first are arranged on the working plane and the second above the same, with the resulting construction complications and costs.
In order to avoid these shortcomings, this invention offers a fastening unit for the items to be processed, comprising a support freely moving along a cross beam mounted on the working plane and equipped with a pair of blocking devices, each including suction cups capable of blocking the item placed on the plane, and pressing elements capable of clamping the piece at an edge, while still resting on the working plane.
This invention will now be described in detail, for exemplifying and non limiting purposes, with reference to the single attached FIGURE which offers a cross-sectional view of the fastening unit according to the invention.